Poultry brooders are used in poultry houses to provide heat and radiant energy in order to keep chicks warm and disease free and to keep the poultry house floor dry.
A typical poultry brooder of the type pertaining to this invention has a ceramic radiant element disposed over a thermostatically controlled gas burner so that the flame and heated gases from the gas burner impinge upon and heat the ceramic radiant. During one cycle of operation the controlling thermostat activates a gas source to supply fuel gas to the main gas burner ignited by an adjacent pilot burner. The main burner remains on until the desired temperature is reached, at which time the thermostatic control terminates the supply of gas to the burner to extinguish the main burner. The pilot burner, on the other hand, remains lit at all times. A poultry brooder generally in accordance with the foregoing description is shown and described in U.S. Letters Patent Nos. 4,614,166 and 4,658,758 issued to Paul E. Maurice.
As previously stated, one goal of the poultry farmer is to keep the chicks and poultry house floor warm and dry. However, since dry feed, feathers and excrement accumulate on the dry dirt poultry house floor and may become airborne with movement of the chicks, the poultry house can become a remarkably dusty environment. Although airborne dust and other particles (hereinafter "dust") generally do not detract from the performance of the main gas burner, the extreme dust conditions in a poultry house can and do affect performance of the pilot burner.
Poultry brooder pilot burners typically have a small orifice on the order of 0.009 to 0.018 inches in diameter mounted in an orifice holder which, in turn, is mounted in a support structure adjacent to the main gas burner. Typically, the orifice is threaded into corresponding threads in the orifice holder which is coupled via a threaded coupling to a gas line. In the poultry brooder shown and described in the foregoing U.S. Pat. No. 4,614,166, as sold by Safe-glo Products of Springfield, Mass., a horizontally mounted pilot burner has a vertical orifice surface and a fixedly mounted pilot burner body for conveying the pilot flame to the main gas burner. In other types of poultry brooders, such as brooders sold by Shenandoah Manufacturing Co., Inc. of Harrisonburg, Va., the pilot burner is vertically mounted adjacent to the main gas burner. In this latter arrangement the orifice surface is horizontal. As will be readily appreciated, a horizontal orifice is highly susceptible to the accumulation of dust on or in the orifice which can often clog the orifice and extinguish the pilot flame. In view of this known drawback, the pilot burner barrel of the foregoing Shenandoah poultry brooder is not firmly attached in any way to the pilot burner support structure. Rather, the rectangular pilot barrel is inserted through a corresponding opening in one metal plate and simply stands vertically on the horizontal pilot burner support surface surrounding the orifice holder. This structure suffers from the additional drawback that the loose pilot barrel is susceptible to being accidentally displaced and, therefore, is of limited value.
When a poultry brooder pilot burner becomes clogged, as by dust becoming lodged in the orifice, the pilot burner eventually becomes unable to ignite the main burner. The pilot burner flame gradually diminishes and the orifice must then be cleaned and/or replaced. Briefly stated, there are two ways to clean and/or replace the orifice.
First, the poultry farmer can attempt to clear the orifice from the "front" or flame side. Where the pilot burner is vertically mounted with a pilot barrel loosely resting on the surrounding support surface this can be accomplished by lifting away the loose pilot barrel and cleaning the orifice either by passing a finger across the orifice surface or inserting a fine wire into the orifice itself. However, the horizontal orifice in a vertical pilot burner is more susceptible to clogging and a loose barrel on vertical pilot burner is prone to being accidentally knocked over. Therefore, these configurations are of limited value.
In the generally preferred configuration wherein the pilot burner is horizontally mounted and necessarily has a fixed pilot barrel, the orifice surface is not readily accessible from the front and this technique is not helpful. In a horizontal pilot burner the poultry farmer can only attempt to clean the orifice from the front to the extent the orifice can be reached through air apertures, if any, provided in the pilot body.
Secondly, the poultry farmer can disassemble the orifice holder from the rear to clean or, where necessary, replace the orifice. Accessing the orifice in this manner becomes necessary when the orifice cannot be cleaned from the front surface, either because the clog in a vertical pilot burner is too severe or because the front of the orifice is not readily accessible for cleaning, as in the preferred horizontally mounted pilot burner wherein the fixed barrel precludes full access to the front of the orifice.
Unfortunately, dismantling the orifice holder requires that the gas source be shut off and that the orifice holder be disconnected from the gas line and pilot burner support using tools, such as one or more wrenches and/or pliers. During reassembly, all gas couplings must be checked for leaks. As will be readily appreciated, accessing the orifice in this manner is inconvenient and time consuming and detracts from the poultry farmer's ability to perform other chores.
In a related problem, it has been observed that as the orifice of a poultry brooder pilot burner becomes clogged, the intensity and effectiveness of the pilot flame diminish gradually. That is, the failure of the pilot flame due to orifice clogging is a gradual deterioration over time and not a sudden occurrence. Given the inherent hazards of fuel gas, Poultry brooders are commonly provided with a safety circuit which is designed to cut off the gas supply and override a thermostatic command to ignite the main burner where a pilot burner failure is detected. To this end, a thermocouple is provided at the pilot burner to detect the presence or absence of a pilot flame. Should the pilot burner thermocouple fail to detect the presence of a pilot flame the safety circuit will prevent any attempt to light the main burner. It has been found, however, that as the pilot flame gradually diminishes during clogging the flame often becomes too weak to ignite the main burner but still strong enough to be detected by the thermocouple. Under these circumstances the safety circuit will not be activated and, during a futile attempt to ignite the main burner, latent fuel gas may be permitted to escape into the poultry house. Naturally, this can present hazards of explosion and asphyxiation.
Therefore, it is one object of the present invention to provide a poultry brooder pilot burner in which the orifice is readily accessible for cleaning.
It is a further object of the present invention to provide a poultry brooder pilot burner having a removable pilot burner barrel which is not susceptible to being accidentally displaced from its operational position.
It is another object of the present invention to provide, in a horizontally mounted poultry brooder pilot burner having a desirable vertical orifice surface, a removable pilot burner barrel to facilitate front surface cleaning of the orifice.
It is a further object of the present invention to provide a horizontally mounted poultry brooder pilot burner in which the orifice can be removed without disconnecting fuel gas couplings.
Yet another object of the present invention is to provide an improved poultry brooder having a safety circuit with a thermocouple sensor wherein the thermocouple is configured and dimensioned to sense only a pilot flame sufficient to ignite the main gas burner.
These and other highly desirable and unusual results are accomplished by the present invention in an economical structure which remarkably permits convenient access to the orifice surface for cleaning without any need for the use of tools or disconnection of any gas line couplings.
Objects and advantages of the invention are set forth in part herein and in part will be obvious herefrom, or may be learned by practice with the invention, which is realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.
The invention consists of the novel parts, constructions, arrangements, combinations, steps, and improvements herein shown and described.